Magnetic separator



1942- M. D. THOMPSON 2,269,397

MAGNETI C S EPARATOR Filed Feb. 20, 1939 MlLLWARD puP'LEy Tmwsou Patented Jan. 13, 1942 MAGNETIC SEPARATOR Millward Dudley Thompson, Birmingham, England Application February 20, 1939, Serial No. 257,511 In Great Britain February 25, 1938 4Claims.

This invention relates to improvements in magnetic separators for the removal of magnetic particles from liquid or semi-liquid materials such as potters slip, glazes, paper pulp, guncotton pulp, and other materials of similar consistency, or for the separation of materials in suspension in a liquid.

Such materials are commonly treated by causing them to fiow under gravity down an inclined tray or trough across which extend a series of spaced magnetic pole-pieces so that any magnetic particles in the material are attracted by and retained on the pole-pieces, and it is usual to provide in the tray or trough upstanding teeth or projections around or over which the material eddies and with which it is brought into intimate contact.

A magnetic separator according to my invention comprises a conduit for the passage of the material to be separated and a foraminous metallic filling which is magnetized and through or over which the material is adapted to pass. The foraminous filling presents a very large surface area to the material and as the material passes through the filling any magnetic particles are picked up and trapped in the filling so that there is no risk of them being carried off again in the flow of the material.

The conduit containing the filling may be made in readily detachable sections or the filling may be contained in readily detachable skeleton frames or boxes so that when the machine is stopped these sections or frames can be lifted out and washed or rinsed to discharge the magnetic particles.

The foraminous filling is conveniently formed by interwoven or intertwined fine steel or iron wire or strip, or of similar material, or it may be made up from a number of strips of perforated metal which are folded and welded or otherwise secured together at the fold to form an elongated member of fan-shape in cross-section. The edges of the strips are preferably cut through a row of perforations so that they are serrated and present sharp edges of considerable length, and these edges and the edges of the holes have a high magnetic intensity in addition to which the holes serve as traps in which magnetic particles are securely held.

One practical form of magnetic separating means in accordance with my invention is illustrated by way of example in the accompanying drawing in whichvation of separating elements adapted to be located in an inclined trough. I

Figure 2 is a similar view showing the direction of fiow of the material through the elements.

Figure 3 is a fragmentary perspective view of a part of a separating trough fitted with our improved separating elements.

The separating elements shown in Figures 1, 2 and 3 are adapted for use with a separator of known type in which the material to be treated flows down an inclined trough such as H! across the bottom of which are arranged spaced transverse steel or iron bars I I of substantial width forming the pole-pieces of electro-magnets arranged below the trough, the bars ll being alternately of opposite polarity.

Each bar I 1 forms the base of a skeleton metal box or frame l2 having a perforated upper side, a perforated lower side, and a perforated cover 13 which is hinged at H to the lower side and is retained by catches [5 on the upper side. The box or frame is filled with a foraminous filling l6 consisting of a mass of interwoven or intertwined fiat steel or iron wire. This filling is magnetised by the bar II and presents a very large surface area as well as a very great length of sharp edge having a high magnetic intensity.

A shallower skeleton box or frame I! having a perforated top or cover I8 is arranged transversely in the trough between adjacent boxes or frames l2 and this is also filled with the same foraminous material, the filling being shown at IS.

The lower side of each box or frame I2 is made higher than the upper side so that the covers are substantially horizontal and the bottom part of each lower side is not perforated. Thus as the material to be treated flows down through each box or frame, as indicated by the arrows in Fig ure 2, it must on entering each box or frame l2 accumulate until it reaches a level sufiicient to pass out of the perforations in the lower side of the box or frame. It then flows over into the box or frame I! and when that is full it fiows into the next box or frame l2 and so on.

Thus the material as it passes through each box or frame is brought into intimate contact with the filling and is thoroughly searched so that all magnetic particles in the material are retained by the filling.

Each of the boxes or frames I! may be spaced from the adjacent bars I l or it may be in contact with one of the bars II and out of contact with Figure 1 is a diagrammatic sectional side elethe other from which it may be separated by an air gap or by a spacing member non-magnetic material.

To remove the magnetic particles when the machine is stopped the boxes or frames can simply be lifted out and washed in running water.

In the case of the boxes or'frames I! the filling only can be lifted out for washing after raising the hinged cover, or the box or frame may be lifted out complete with the bar II which can be apertured to fit over locating studs projecting upwardly from the magnets through the base of the trough.

The bars Il may rest on a strip of rubber on the floor of the trough to prevent material under treatment from passing below the bars.

I claim:

1. A magnetic separator for treating liquid or semi-liquid material comprising an inclined trough down which the material is adapted to be fed, magnetic bars arranged transversely in the bottom of said trough and spaced along the length thereof, metal boxes overlying said bars of brass or other 'and disposed in the path of flow of said material each of said boxes being provided with perforated upper and lower sides and with a perforated cover, and foraminous magnetizable filling in said boxes.

2. A magnetic separator for treating liquid or semi-liquid material comprising an inclined trough down which the material is adapted to be fed, magnetic bars arranged transversely in the bottom of said trough and spaced along the length fed, magnetic barsarranged transversely in the bottom of said trough and spaced along the length thereof, perforated metal boxes overlying said bars, similar boxes of lesser height intermediate said boxes, said boxes each being provided with a perforated cover, a foraminous magnetizable filling in said boxes, said boxes being detachable from said trough for washing magnetic particles out of said filling.

4. A magnetic separator according to claim 1, in which the lower part of the side of each of said boxes nearest the lower end of the trough is imperforate, whereby material admitted into each box must accumulate therein to a predetermined depth before it can flow out.

MILLWARD DUDLEY THOMPSON. 

